YahhoSpeaking to reporters at Yahoo’s Brickhouse facility in San Francisco, Ash Patel, executive vice president of Yahoo’s Audience Product Division and a panel of execs and managers spelled out the company’s “Rewiring Yahoo” plan, which establishes a “front door” for developers into its evolving Open Stack of platform services. The stack comprises an application platform, a social platform, and a query language, all supported by Yahoo’s infrastructure and providing access to its mail and search services, its media, and its partner sites.

Under the Y!OS banner, Yahoo is providing three new components: the Yahoo Application Platform (YAP), the Yahoo Social Platform (YSP), and the Yahoo Query Language, (YQL). YAP is a framework for building Web applications that can be distributed across Yahoo; YAP includes a set of APIs (social directory, contacts, status and update), which provide access to Yahoo user data and activity streams; YQL is a SQL-like query language for accessing Yahoo data.

Search MonkeyY!OS was announced in April, and followed shortly after by the launch of SearchMonkey, Yahoo’s online development platform and toolset for utilizing the structured data collected online by Yahoo Search. The company later unveiled Yahoo Search BOSS (Build Your Own Search Service), a Web services platform designed to allow developers to tap into Yahoo’s search infrastructure.

The YSP will bring “a social dimension to what Yahoo does,” explained Jay Rossiter, head of Yahoo’s Open Strategy. “It will, essentially, rewire Yahoo as we put different social extensions, create a common social piece, and open up Yahoo’s properties across the board… And we’re going to allow developers to build applications that bring that social experience to the users.”

Open SocialDevelopers will access the YSP via specific RESTful APIs: the Social API will provide a way to query a user’s profile data and connections data; the Presence API will allow devs to update a user’s presence across the network. The APIs will be based on OpenSocial, a set of common APIs for Web-based social network apps, which Google developed. Apps implementing Open Social APIs can work with any social network.

He wouldn’t say exactly when, but Sam Pullara, head of Yahoo’s application platforms group, promised that the YAP tools would be appearing on the Yahoo Developer Network sometime this week.